FILE - In this Nov. 5, 2017, file photo, Denver Broncos' Mike McCoy walks the field before an NFL football game against the Philadelphia Eagles in Philadelphia. The Broncos have fired offensive coordinator Mike McCoy and are replacing him with quarterbacks coach Bill Musgrave. "I have a responsibility to do what's best for our football team," coach Vance Joseph said in a statement ahead of his Monday, Nov. 20, 2017, news conference. "Although this wasn't an easy decision, we needed to make this change. We have to play a more efficient brand of football offensively as we begin the final stretch of our season."(AP Photo/Matt Rourke, File)

ALAMEDA, Calif. (AP) — It's time to see conclusively if quarterback Paxton Lynch is a bust or just a late bloomer.

The Denver Broncos' former first-round draft pick will make his first start this weekend at Oakland, a person with knowledge of the decision told The Associated Press on Tuesday.

The person spoke on condition of anonymity because Denver coach Vance Joseph won't announce his starter until Wednesday.

General manager John Elway moved up in the first round of the 2016 NFL draft to select Lynch with the 26th overall pick, but the former Memphis QB proved to be a project.

Trevor Siemian, a 2015 seventh-rounder from Northwestern, handily beat out Lynch in 2016 and again this season. Shortly after coming up short in Denver's quarterback competition for the second time, Lynch bruised his throwing shoulder against Green Bay in a preseason game.

That led to the re-signing of Peyton Manning's longtime backup, Brock Osweiler, who had been released by Cleveland following a trade from Houston.

Osweiler supplanted a turnover prone Siemian (10 interceptions, two lost fumbles) three weeks ago but went winless in his three starts, including a 20-17 defeat to Cincinnati on Sunday in which Lynch was active for the first time.

McCoy raised eyebrows with his overly complex game plans and stubbornness in sticking to three-receiver formations despite a flurry of sacks, flags and turnovers that resulted from a porous line and lack of depth at tight end and wide receiver.

Joseph said he wanted Musgrave, who guided the Raiders' offense from 2015-16, to simplify the game plans.

Although no team has ever recovered from a 3-7 start to reach the playoffs, it will be interesting to see how Lynch's promotion is met in the locker room.

Teammates have been effusive in their praise of the work ethic and leadership displayed by Osweiler and Siemian and they usually speak in terms of promise and potential when talking about Lynch, who's never been known to get to work first and leave last like so many quarterbacks do.

Last week, when Lynch worked as the backup at practice for the first time and even handled some passing plays with the starters, wide receiver Emmanuel Sanders praised Osweiler's energy and experience that he brought to the equation and said what Lynch brings is a promising upside if he ever buckles down.

"Brock, he's been there before, he's been groomed by Peyton, so he understands the ins and outs of how to play quarterback," Sanders said. "Paxton has a big-time arm, big-time talent. He has all the intangibles. It's all about going out and getting more and more comfortable with the playbook, learning and growing as a player, becoming a pro."

Lynch went 1-1 last year in place of an injured Siemian, losing to Atlanta and beating Jacksonville. He completed 49 of 83 passes for 497 yards and two TDs to go with an interception. He was sacked nine times.

He had to learn a new system when Gary Kubiak stepped down and was replaced by Joseph, who brought in McCoy to replace Rick Dennison.

With Musgrave's promotion, Lynch will be working under his third system in less than two years in the NFL, albeit one that will be pared down for him.

He'll face a Raiders defense going through its own shakeup . The Raiders fired defensive coordinator Ken North Jr. on Tuesday and coach Jack Del Rio handed those duties over to assistant head coach John Pagano.